Why did "subject" pop up above "iMessage" in the app messages?

[erinweafer]

When I went to text someone, the word "subject" is now there in a new little section above "iMessage," as if it were an email!

 

[Tartarus]

Go to Settings > Messages and disable Show Subject Field.

As to why it's enabled, I don't have an earthly idea.

 

[Ledsteplin]

I like using the subject field. Sometimes settings get out of whack with updates and resets.